THE NATURE OF THE CONDUCTANCE INCREASE INDUCED BY FILIPIN IN CHOLESTEROL-CONTAINING PLANAR LIPID BILAYERS

被引:5
作者
KRAWCZYK, J [1 ]
CUKIERMAN, S [1 ]
机构
[1] UNIV CALIF RIVERSIDE,DIV BIOMED SCI,RIVERSIDE,CA 92521
关键词
FILIPIN; LIPID BILAYER; CONDUCTANCE; CHOLESTEROL;
D O I
10.1016/0005-2736(91)90353-A
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
The effects of the polyene antibiotic filipin on the conductance and permeability of planar lipid bilayers were investigated under voltage-clamp conditions. The membrane conductance of lipid bilayers containing no cholesterol was not affected by filipin. In the presence of cholesterol containing lipid bilayers, filipin induced a 10(4)-10(5)-fold increase in transmembrane conductance. This conductance increase was dependent on the ionic species present in solution, decreasing in the following order: G(CsCl) > G(NaAc) > G(KCl) > G(CaCl2) > G(Na2SO4) > G(BaCl2) > G(MgCl2. Reversal potential measurements in simple biionic conditions revealed the following relative permeability sequence: P(K) > P(Cl) > P(Na) almost-equal-to P(ac) almost-equal-to P(Ba) > P(Cs) > P(Mg) almost-equal-to P(Ca) > P(sulphate). The filipin-sterol mediated increase in membrane conductance was independent of the membrane potential. The increase in membrane current following a step alteration in membrane potential occurred instantaneously and had no dependence on the previous value of the holding membrane potential. We propose that the filipin-sterol complex forms ion channels in lipid membranes. These channels are found in a single configuration (open state) and select preferentially monovalent cations or anions over divalent ions. Our experimental results are discussed in relation to the effects of other polyene antibiotics on the membrane permeability, and also in relation to experimental problems previously reported with the use of filipin in planar lipid bilayers.
引用
收藏
页码:60 / 66
页数:7
相关论文
共 16 条
[1]   INTERACTION OF POLYENE ANTIBIOTICS WITH THIN LIPID MEMBRANES [J].
ANDREOLI, TE ;
MONAHAN, M .
JOURNAL OF GENERAL PHYSIOLOGY, 1968, 52 (02) :300-+
[3]   THE K+ CHANNEL OF SARCOPLASMIC-RETICULUM - A NEW LOOK AT CS+ BLOCK [J].
CUKIERMAN, S ;
YELLEN, G ;
MILLER, C .
BIOPHYSICAL JOURNAL, 1985, 48 (03) :477-484
[5]  
Finkelstein A, 1973, Membranes, V2, P377
[6]   CHANNELS FORMED BY BOTULINUM, TETANUS, AND DIPHTHERIA TOXINS IN PLANAR LIPID BILAYERS - RELEVANCE TO TRANSLOCATION OF PROTEINS ACROSS MEMBRANES [J].
HOCH, DH ;
ROMEROMIRA, M ;
EHRLICH, BE ;
FINKELSTEIN, A ;
DASGUPTA, BR ;
SIMPSON, LL .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1985, 82 (06) :1692-1696
[7]  
KINSKY SC, 1966, FED PROC, V25, P1503
[8]  
LAMPEN JO, 1906, BIOCH STUDIES ANTIMI, P111
[9]   ION-TRANSPORT THROUGH PORES - RATE-THEORY ANALYSIS [J].
LAUGER, P .
BIOCHIMICA ET BIOPHYSICA ACTA, 1973, 311 (03) :423-441
[10]   COMPETITION BETWEEN CHOLESTEROL AND PHOSPHOLIPIDS FOR BINDING TO FILIPIN [J].
MILHAUD, J ;
MAZERSKI, J ;
BOLARD, J .
BIOCHIMICA ET BIOPHYSICA ACTA, 1989, 987 (02) :193-198